daiken ducted aircondition malfunction ..PLEASE HELP....

[kakka]

Hi guys, Iam new to this forum. I just need some help with the malfunction code appeared on the controll panael of the ducted air conditioner. It reads as U4 which i understood that it is System Transmission between indoor units. What do I do to fix it? When I pressed on one of the button thats when it appeared. Also the operation re/green button flashing as well. What do I do? is it serious? Please help..........
thanks kakka...

[The Viking]

U4, is communication between indoor unit and outdoor unit (or outdoor unit and BC box).

The normal reason for this code to flag up is in multi indoor applications where the indoor units got their own electrical supply, someone has isolated the power to the outdoor unit.

Should this not be the case, you are looking at communication wiring/transformers/PCBs.

Good hunting.